Endothermic ReactionSolid barium hydroxide octahydrate (Ba(OH)2*8H2O) and ammonium thiocyanate (NH4SCN) are mixed in a beaker, which is then placed on a few drops of water on a small board. The reaction that occurs is highly endothermic.

Calorimetry / Thermochemistry |

Thermodynamics

Sulfuric Acid into Water and IceWhen sulfuric acid is mixed with water the temperature rises. When sulfuric acid is added to ice, the temperature rises at first, but as the ice melts, the temperature falls.

Thermochemistry : SystemSurrExoEndo (4 Variations)
Sulfuric acid is added to water in a beaker and the resulting solution is much warmer than either the water or acid was initially.
Identify the following items as being part of the system or the surroundings, and indicate whether the process is exothermic or endothermic.

The Correlation of Binary Acid Strengths with Molecular Properties in First-Year ChemistryTravis D. FridgenThis article replaces contradictory explanations for the strengths of different binary acids in first-year chemistry textbooks with a single explanation that uses a BornHaber cycle involving homolyic bond dissociation energies, electron affinities, and ion solvation enthalpies to rationalize trends in the strengths of all binary acids.Fridgen, Travis D. J. Chem. Educ.2008, 85, 1220.

Acids / Bases |

Atomic Properties / Structure |

Aqueous Solution Chemistry |

Physical Properties |

Thermodynamics

Appreciating OxygenHilton M. WeissPhotosynthetic flora and microfauna utilize light from the sun to convert carbon dioxide and water into carbohydrates and oxygen. While these carbohydrates and their derivative hydrocarbons are generally considered to be fuels, it is the thermodynamically energetic oxygen molecule that traps, stores, and provides almost all of the energy that powers life on earth.Weiss, Hilton M. J. Chem. Educ.2008, 85, 1218.